A208353 T(n,k) is the number of n X k 0..3 arrays with new values 0..3 introduced in row major order and no element equal to any knight-move neighbor (colorings ignoring permutations of colors).

1, 2, 2, 5, 15, 5, 15, 100, 100, 15, 51, 868, 1095, 868, 51, 187, 7780, 12625, 12625, 7780, 187, 715, 69988, 153237, 230387, 153237, 69988, 715, 2795, 629860, 1901508, 4773885, 4773885, 1901508, 629860, 2795, 11051, 5668708, 23658861, 103672036

Offset

1,2

Links

R. H. Hardin, Table of n, a(n) for n = 1..83

Example

Table starts:
....1.......2.........5..........15.............51............187
....2......15.......100.........868...........7780..........69988
....5.....100......1095.......12625.........153237........1901508
...15.....868.....12625......230387........4773885......103672036
...51....7780....153237.....4773885......191586797.....8045978096
..187...69988...1901508...103672036.....8045978096...647640659639
..715..629860..23658861..2280287753...340596199800.52428246114853
.2795.5668708.294608660.50481169071.14513602070899
Some solutions for n=4 and k=3:
..0..0..0....0..0..0....0..0..0....0..0..0....0..1..0....0..0..0....0..0..0
..1..0..1....1..1..1....1..2..1....1..1..1....1..2..2....1..1..1....1..0..1
..2..1..2....2..1..2....2..1..3....2..1..2....3..2..2....2..1..2....2..2..2
..1..2..1....3..2..3....0..0..1....0..2..0....1..3..0....3..2..0....1..2..3

Crossrefs

Main diagonal is A208346.

Columns 1..7 are A007581(n-1), A208347, A208348, A208349, A208350, A208351, A208352.

Sequence in context: A176856 A112709 A291573 * A208001 A200801 A241119

Adjacent sequences: A208350 A208351 A208352 * A208354 A208355 A208356

Keyword

nonn,tabl

Author

R. H. Hardin, Feb 25 2012

Status

approved